Electrical regenerative control apparatus and system.



J. G. MAOFARLANE & H. BURGE.

ELECTRICAL REGENBBATIVE CONTROL APPARATUS AND SYSTEM.

APPLICATION FILED IEIB. 7, 1910. I 998,364, Patented July 18,1911.

'wzeaaezsa UNITED STATES il li l lilil.

JAMES COLQUHOUN MACFAH-LANE AND HARRY BTJ'IEGE. OF $33 WORKS, CHIELEESFORD, ENGLAND, ASSIGN'ORS TO THE FIRM 0 CROMETGN AND COMPANY LIMITED, 01?

ARC WORKS, CHELMSFORD. ENGLAND.

Specification of Letters Pate t.

i a'ltented July 18., 1311.

Application filed February 7. 1910. Serial No. 5412.483.

To all whom it may concern:

Be it known that we Janus COLQUHOUN MAo/mnmxn and HARRY Boron, subjects of the King of Great Britain. residing at Arc" Works, Chelmsford. in the county of Essex.

England, have invented certain new and useful Improvements in Electrical Regenerative Control Apparatus and Systems of which the following is a specification.

This invention relates to improvements in electrical regenerative control apparatus and systems such for example as are applied to trains, tramway ears. omnibuses fly'wheel storage systems, and the like, and tho invention has for its object to provide means for automatically lining a safe limit to the current drawn from the supply mains and passing through the driven motor or motors.

According to the invention the. apparatus comprises a motor-generator and one or more motors. all coupled together on the well known Ward-Leonard system, and to this system is applied. a safety winding. consisting of a series field winding which is provided upon the generator element of the motor-generator. v

The accompanying drawing; shows a diagram of a. motor-generator the dynamo poi tion of which is coupled in series with a motor across the line, the dynamo being provided with an auxiliary winding, the subject of this invention.

A and B are the motor and the generator elements respectively of a motor-generator, and C is Lt-driven motor connected in series with the generator element B. A. reversible shunt regulator E controls the field K of the generator element B in such a way that any voltage from zero to approximately twicethe supply voltage V may be impressed on the motor (l. The generator element is provided as shown in the drawing with a series field Winding G WllQI'GOii the magnetomotive-forcc 7's in opposition to the magnetoinotive-torce of the field winding K on the generator element B when the motor C running as a motor at full speed, but when the motor (l is li-ll'tlltlflilllg at full speed, i. 6.. returning current to the line. the magneto-motive-force ot the series field winding (i is exerted in the same direction as that of the field windinp K. With this combination of series field winding G and field winding li. it will he seen that the series field winding; can, it properly proportioned, he made to automatically regulate the electrouiotivo'torce oi the. generator elcment B in such a manner that under any conditions the current passing through the motors cannot exceed a predetermined value. As an. ample, suppose the pressure across the line is 100 volts and that the generator B ruin ning at a constant speed and with a maximum positive excitation produces an additional 100 volts pressure making a total pres sure on the element. C of 200 volts. It the excitation of the generator B be now reversed hy means of the shunt regulator E, it will exert a counter electro-motive-force of 100 volts and the pressure on the element (l willconsequently be Zero. Any variation from no volts to 260 volts can therefore be impressed on the elment C, by means of the shunt coil K which is. therefore, the controlling field element. 'When the element C is acting as a motor the current taken by it depends on the load. it the load becomes very heavy and the speed of the motor C, in conseouence falls. its back electro-inot1ve-2' force will he reduced. and consequently it the dynamo E. is still supplying energy at a pressure of 260 volts a very large current..

would flow From the generator to the motor. According to this invention, this current is automatically reduced by means of the series field-winding; G which serves to Clo-magnetinc the generator ll when current is flowing: from the generator to the motor. As such ti -magnetization is proportional to the current flowing it is clear that when the element C is acting as a motor. the series field winding G will prevent such current from rising to an abnormal value. The same effect produced when owing to the flywheel e Iectv of the element. C or the inomentum oi the load. the element C continues running although all driving force is removed owing to the voltage delivered to the clement having been reduced to zero by means of the rheostat in this case, if the element t is still running at nearly its fullfield winding G, in the reverse direction, it

This will tend to will i'nagnetize the generator B positively and such generator B will consequently produce an electro-motive-force in a positive direction opposing such current. Consequently, when the element 0 is acting as a generator and returning en ergy'to the line,

- the series field Winding G will again prethe element (1 is acting as a motor or a genorator. Generally the windings K and G oppose each other, but a case may arise when it is desired to reduce the speed, where the regulator E has not been actually reversed so that the generator is still giving a low positive voltage which is not suiiicient to keep the reverse current from the element 0 within safe limits, and in that case, the winding G will produce a positive field of the same sign as that of the winding K and of greater magnitude. lleuce cases may eases-e arise in which the field due to the winding G is greater than that due to the winding K.

What we claim is r 1. An electrical regenerative control system comprising a motor generator having a motor element and a generator element, a motor connected in series with said generator element, a reversible shunt regulator for control-ling the field of said generator element so that any voltage from Zero to approximately twice the supply voltage may be impressed upon said motor, and means upon said generator element for limiting the our rent drawn from the supply mains.

2. An electrical regenerative control system comprising, a motor generator having a motor element and a generator element, a motor connected in series with said generator element, a reversible shunt regulator for controlling the field of said generator element, and a series field winding upon said generator element for limiting the current drawn from the supply mains.

In testimony whereof we have hereunto set our hands in presence of two subscribing witnesses.

JAS. COLQUHOUN MACFARLANE. HARRY B RoE. Witnesses:

llama J, S'roennN, E :xnsr Jenn HILL. 

